feat: expand chains (+6 testnets) and tokens (+EURC, WETH, USDT)

src/constants.ts

@@ -1,4 +1,5 @@
 import { parseAbi } from 'viem'
+import type { CredentialType } from './types.js'
 
 export type SupportedChain =
   | 'base'
@@ -10,6 +11,12 @@ export type SupportedChain =
   | 'linea'
   | 'unichain'
   | 'base-sepolia'
+  | 'ethereum-sepolia'
+  | 'arbitrum-sepolia'
+  | 'optimism-sepolia'
+  | 'polygon-amoy'
+  | 'scroll-sepolia'
+  | 'linea-sepolia'
 
 export const CHAIN_IDS: Record<SupportedChain, number> = {
   base: 8453,
@@ -21,6 +28,12 @@ export const CHAIN_IDS: Record<SupportedChain, number> = {
   linea: 59144,
   unichain: 130,
   'base-sepolia': 84532,
+  'ethereum-sepolia': 11155111,
+  'arbitrum-sepolia': 421614,
+  'optimism-sepolia': 11155420,
+  'polygon-amoy': 80002,
+  'scroll-sepolia': 534351,
+  'linea-sepolia': 59141,
 }
 
 export const USDC_CONTRACTS: Record<SupportedChain, `0x${string}`> = {
@@ -33,6 +46,12 @@ export const USDC_CONTRACTS: Record<SupportedChain, `0x${string}`> = {
   linea: '0x176211869cA2b568f2A7D4EE941E073a821EE1ff',
   unichain: '0x078D782b760474a361dDA0AF3839290b0EF57AD6',
   'base-sepolia': '0x036CbD53842c5426634e7929541eC2318f3dCF7e',
+  'ethereum-sepolia': '0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238',
+  'arbitrum-sepolia': '0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d',
+  'optimism-sepolia': '0x5fd84259d66Cd46123540766Be93DFE6D43130D7',
+  'polygon-amoy': '0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582',
+  'scroll-sepolia': '0x4d7ff95a5e86b0aaade01df5adadded72c54a698',
+  'linea-sepolia': '0xFEce4462D57bD51A6A552365A011b95f0E16d9B7',
 }
 
 export const DEFAULT_CONFIRMATIONS: Record<SupportedChain, number> = {
@@ -45,6 +64,79 @@ export const DEFAULT_CONFIRMATIONS: Record<SupportedChain, number> = {
   linea: 1,
   unichain: 1,
   'base-sepolia': 1,
+  'ethereum-sepolia': 0,
+  'arbitrum-sepolia': 0,
+  'optimism-sepolia': 0,
+  'polygon-amoy': 0,
+  'scroll-sepolia': 0,
+  'linea-sepolia': 0,
+}
+
+export type SupportedToken = 'USDC' | 'EURC' | 'WETH' | 'USDT'
+
+// `Partial` because not every token is deployed on every chain. Admin layer
+// must reject creating a payment option for a (chain, token) pair that
+// resolves to undefined.
+//
+// Provenance rule (see agent-proxy/docs/decisions.md): every entry must be
+// either issuer-deployed (Circle for USDC/EURC, Tether for mainnet USDT,
+// chain team for canonical WETH wrappers) or verified on-chain against a
+// known audited bytecode hash. Community-deployed tokens are not first-class.
+//
+// WETH carve-out: only canonical native ETH wrappers are listed. Polygon
+// (native MATIC) and Avalanche (native AVAX) carry "WETH" only as bridged
+// assets, which is a different trust model — those entries are intentionally
+// absent.
+export const TOKEN_CONTRACTS: Record<
+  SupportedToken,
+  Partial<Record<SupportedChain, `0x${string}`>>
+> = {
+  USDC: { ...USDC_CONTRACTS },
+  EURC: {
+    ethereum: '0x1aBaEA1f7C830bD89Acc67eC4af516284b1bC33c',
+    base: '0x60a3E35Cc302bFA44Cb288Bc5a4F316Fdb1adb42',
+    avalanche: '0xC891EB4cbdEFf6e073e859e987815Ed1505c2ACD',
+    'ethereum-sepolia': '0x08210f9170f89ab7658f0b5e3ff39b0e03c594d4',
+  },
+  WETH: {
+    ethereum: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
+    base: '0x4200000000000000000000000000000000000006',
+    optimism: '0x4200000000000000000000000000000000000006',
+    arbitrum: '0x82aF49447D8a07e3bd95BD0d56f35241523fBab1',
+    linea: '0xe5D7C2a44FfDDf6b295A15c148167daaAf5Cf34f',
+    unichain: '0x4200000000000000000000000000000000000006',
+    'ethereum-sepolia': '0x7b79995e5f793a07bc00c21412e50ecae098e7f9',
+    'arbitrum-sepolia': '0x2836ae2ea2c013acd38028fd0c77b92cccfa2ee4',
+    'polygon-amoy': '0x52ef3d68bab452a294342dc3e5f464d7f610f72e',
+    'scroll-sepolia': '0x5300000000000000000000000000000000000004',
+  },
+  // Mainnet only — Tether issues these. Testnet USDT is intentionally absent
+  // because the candidates are community deployments without provenance.
+  USDT: {
+    ethereum: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
+    arbitrum: '0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9',
+    optimism: '0x94b008aA00579c1307B0EF2c499aD98a8ce58e58',
+    polygon: '0xc2132D05D31c914a87C6611C10748AEb04B58e8F',
+    avalanche: '0x9702230A8Ea53601f5cD2dc00fDBc13d4dF4A8c7',
+  },
+}
+
+export const TOKEN_DECIMALS: Record<SupportedToken, number> = {
+  USDC: 6,
+  EURC: 6,
+  WETH: 18,
+  USDT: 6,
+}
+
+// Per-token credential-type compatibility. EIP-3009 transferWithAuthorization
+// is implemented by Circle's FiatToken family (USDC, EURC). WETH and USDT
+// lack it (USDT mainnet uses its own non-standard approve/transferFrom),
+// so those tokens accept Permit2 + on-chain hash only.
+export const TOKEN_CREDENTIAL_TYPES: Record<SupportedToken, readonly CredentialType[]> = {
+  USDC: ['permit2', 'authorization', 'hash'],
+  EURC: ['permit2', 'authorization', 'hash'],
+  WETH: ['permit2', 'hash'],
+  USDT: ['permit2', 'hash'],
 }
 
 export const PERMIT2_ADDRESS: `0x${string}` = '0x000000000022D473030F116dDEE9F6B43aC78BA3'
@@ -91,6 +183,12 @@ export const CHAIN_SLUGS: Record<SupportedChain, string | null> = {
   linea: 'linea-mainnet',
   unichain: 'unichain-mainnet',
   'base-sepolia': 'base-sepolia',
+  'ethereum-sepolia': 'ethereum-sepolia',
+  'arbitrum-sepolia': 'arbitrum-sepolia',
+  'optimism-sepolia': 'optimism-sepolia',
+  'polygon-amoy': 'matic-amoy',
+  'scroll-sepolia': 'scroll-sepolia',
+  'linea-sepolia': 'linea-sepolia',
 }
 
 /**

src/index.ts

@@ -1,4 +1,9 @@
-export type { SupportedChain } from './constants.js'
+export type { SupportedChain, SupportedToken } from './constants.js'
+export {
+  TOKEN_CONTRACTS,
+  TOKEN_CREDENTIAL_TYPES,
+  TOKEN_DECIMALS,
+} from './constants.js'
 export { QuickNodeRateLimitError } from './errors.js'
 export { charge } from './Methods.js'
 export type {

src/internal/chain.ts

@@ -1,13 +1,19 @@
 import type { Chain } from 'viem'
 import {
   arbitrum,
+  arbitrumSepolia,
   avalanche,
   base,
   baseSepolia,
   linea,
+  lineaSepolia,
   mainnet,
   optimism,
+  optimismSepolia,
   polygon,
+  polygonAmoy,
+  scrollSepolia,
+  sepolia,
   unichain,
 } from 'viem/chains'
 import type { SupportedChain } from '../constants.js'
@@ -22,6 +28,12 @@ const chains: Record<SupportedChain, Chain> = {
   linea,
   unichain,
   'base-sepolia': baseSepolia,
+  'ethereum-sepolia': sepolia,
+  'arbitrum-sepolia': arbitrumSepolia,
+  'optimism-sepolia': optimismSepolia,
+  'polygon-amoy': polygonAmoy,
+  'scroll-sepolia': scrollSepolia,
+  'linea-sepolia': lineaSepolia,
 }
 
 export function getViemChain(chain: SupportedChain): Chain {

src/server/Charge.ts

@@ -7,18 +7,20 @@ import {
   defaultRpcUrl,
   ERC20_ABI,
   PERMIT2_ADDRESS,
-  USDC_CONTRACTS,
+  type SupportedToken,
+  TOKEN_CONTRACTS,
+  TOKEN_CREDENTIAL_TYPES,
+  TOKEN_DECIMALS,
 } from '../constants.js'
 import { resolveSigner } from '../internal/account.js'
 import { logDefaultTransportOnce } from '../internal/transport.js'
 import { charge as chargeMethod } from '../Methods.js'
-import {
-  type AuthorizationPayload,
-  type CredentialType,
-  credentialTypes,
-  type HashPayload,
-  type Permit2Payload,
-  type ServerParameters,
+import type {
+  AuthorizationPayload,
+  CredentialType,
+  HashPayload,
+  Permit2Payload,
+  ServerParameters,
 } from '../types.js'
 import { getPublicClient, getWalletClient } from './rpc.js'
 import { verifyAuthorization } from './verifiers/authorization.js'
@@ -52,8 +54,32 @@ export function charge(parameters: ServerParameters) {
     store: storeInput,
     submitter,
   } = parameters
-  const acceptedTypes: readonly CredentialType[] = acceptedTypesInput ?? credentialTypes
-  const tokenAddress = USDC_CONTRACTS[chain]
+  const tokenSymbol: SupportedToken = parameters.token ?? 'USDC'
+  const tokenAddress = TOKEN_CONTRACTS[tokenSymbol]?.[chain]
+  if (!tokenAddress) {
+    const supportedOnChain = (Object.keys(TOKEN_CONTRACTS) as SupportedToken[])
+      .filter((t) => TOKEN_CONTRACTS[t][chain])
+      .join(', ')
+    throw new Error(
+      `${tokenSymbol} is not deployed on ${chain}. Supported tokens for this chain: ${
+        supportedOnChain || '(none)'
+      }`,
+    )
+  }
+  const tokenDecimals = TOKEN_DECIMALS[tokenSymbol]
+  const allowedTypes = TOKEN_CREDENTIAL_TYPES[tokenSymbol]
+  // When the caller omits `credentialTypes`, default to the per-token allowed
+  // set rather than the universal one. Otherwise tokens like WETH and USDT —
+  // which lack EIP-3009 — would throw on every zero-config construction
+  // because the universal default includes 'authorization'.
+  const acceptedTypes: readonly CredentialType[] = acceptedTypesInput ?? allowedTypes
+  const invalidTypes = acceptedTypes.filter((t) => !allowedTypes.includes(t))
+  if (invalidTypes.length) {
+    throw new Error(
+      `${tokenSymbol} does not support credential types: ${invalidTypes.join(', ')}. ` +
+        `Supported on ${tokenSymbol}: ${allowedTypes.join(', ')}.`,
+    )
+  }
   const chainId = CHAIN_IDS[chain]
   const confirmations = confirmationsInput ?? DEFAULT_CONFIRMATIONS[chain]
   const store = storeInput ?? (Store.memory() as NonNullable<ServerParameters['store']>)
@@ -111,7 +137,7 @@ export function charge(parameters: ServerParameters) {
   return Method.toServer(chargeMethod, {
     defaults: {
       currency: tokenAddress,
-      decimals: 6,
+      decimals: tokenDecimals,
       recipient,
     },
     async request({ request }) {

src/types.ts

@@ -1,5 +1,5 @@
 import type { Account, Address, Hash, Hex } from 'viem'
-import type { SupportedChain } from './constants.js'
+import type { SupportedChain, SupportedToken } from './constants.js'
 
 export const credentialTypes = ['permit2', 'authorization', 'hash'] as const
 
@@ -48,8 +48,14 @@ export type ServerParameters = {
   rpcUrl?: string
   /** Target chain for settlement. */
   chain: SupportedChain
-  /** ERC-20 token symbol — resolves to a contract address via the chain's token map. @default 'USDC' */
-  token?: 'USDC'
+  /**
+   * ERC-20 token symbol — resolves to a contract address via TOKEN_CONTRACTS.
+   * Testnet token availability is sparse outside USDC: EURC ships only on
+   * ethereum-sepolia, WETH on a subset of testnets. Authorization (EIP-3009)
+   * is supported only by Circle's FiatToken family (USDC, EURC); WETH is
+   * permit2 + hash only. @default 'USDC'
+   */
+  token?: SupportedToken
   /**
    * Accepted credential types, advertised in the challenge. Ordered from most to
    * least preferred (draft-evm-charge-00 §3). @default ['permit2','authorization','hash']